Stroke is the leading cause of adult disability in the US and the third leading cause of death. More than half of ischemic stroke patients have sleep apnea, a very common and important risk factor for incident stroke and potentially a risk factor for poor stroke outcome. No published studies have established the prevalence of sleep apnea in Hispanics to discern sleep apnea's contribution to excess stroke burden in this large minority group. Small studies conducted in academic medical centers have suggested that stroke patients with sleep apnea have particularly poor stroke outcomes, but population-based studies in diverse populations are lacking. Even fewer data exist about the relationship between sleep apnea and recurrent stroke and mortality, potential targets for a clinical trial of sleep apnea treatment in stroke patients. The parent study for this project, the Brain Attack Surveillance in Corpus Christi (BASIC) project, is an ongoing population-based stroke surveillance study that identifies stroke cases in Nueces County, Texas. This study has made many important discoveries about stroke in Hispanics, the largest minority group in the US, and non-Hispanic whites. BASIC, which was recently renewed for another 5 years (February, 2009 - January, 2014), will continue to identify all ischemic strokes in Nueces County and will provide detailed 90-day stroke outcome data (cognitive, functional, neurologic, and quality of life). In the current proposal we add ancillary studies to this project including physiological and questionnaire-based sleep apnea screening in the acute stroke period. We propose to relate these data to 90-day outcomes and long term stroke recurrence and death risk. Given that outcome assessment is currently underway and will cease in March 31, 2013, it is critical to begin sleep apnea screening as soon as possible to maximize the power for the given study objectives. The ancillary studies will allow us to answer important, novel questions about sleep-disordered breathing and its relationship to stroke and stroke outcomes within a bi-ethnic community in a cost-containing fashion, as we will use the BASIC infrastructure for case identification and outcome data collection. This proposal seeks to understand the influence of a very frequent risk factor, sleep apnea, on a common, devastating disease, stroke, in the largest and fastest growing US minority population.